The three Navy SEALs stomped on the bound Afghan detainees and dropped heavy stones on their chests, the witnesses recalled. They stood on the prisoners’ heads and poured bottles of water on some of their faces in what, to a pair of Army soldiers, appeared to be an improvised form of waterboarding.

A few hours earlier, shortly after dawn on May 31, 2012, a bomb had exploded at a checkpoint manned by an Afghan Local Police unit that the SEALs were training. Angered by the death of one of their comrades in the blast, the police militiamen had rounded up half a dozen or more suspects from a market in the village of Kalach and forced them to a nearby American outpost. Along the way, they beat them with rifle butts and car antennas.

A United States Army medic standing guard at the base, Specialist David Walker, had expected the men from SEAL Team 2 to put a stop to the abuse. Instead, he said, one of them “jump-kicked this guy kneeling on the ground.” Two others joined in, Specialist Walker and several other soldiers recounted, and along with the Afghan militiamen, they beat the detainees so badly that by dusk, one would die.

The four American soldiers working with the SEALs reported the episode, which has not previously been disclosed. In a Navy criminal investigation, two Navy support personnel said they had witnessed some abuse by the SEALs, as did a local police officer. Separately, an Afghan detained with the man who died provided a detailed account of mistreatment by American troops and Afghan militiamen in an interview with The New York Times.

The SEAL command, though, cleared the Team 2 members of wrongdoing in a closed disciplinary process that is typically used only for minor infractions, disregarding a Navy lawyer’s recommendation that the troops face assault charges and choosing not to seek a court-martial. Two of the SEALs and their lieutenant have since been promoted, even though their commander in Afghanistan recommended that they be forced out of the elite SEAL teams.

“It just comes down to what’s wrong and what’s right,” Specialist Walker said in a recent interview. “You can’t squint hard enough to make this gray.”

Even before the beatings, some of the SEALs had exhibited troubling behavior. According to the soldiers and Afghan villagers, they had amused themselves by tossing grenades over the walls of their base, firing high-caliber weapons at passing vehicles and even aiming slingshots at children, striking them in the face with hard candy.

Abuse of detainees is among the most serious offenses an American service member can commit. Several military justice experts, who reviewed a Naval Criminal Investigative Service report on the case at the request of The Times, said that it had been inappropriate for the SEAL command to treat such allegations as an internal disciplinary matter and that it should have referred the case for an Article 32 review, the equivalent of a grand jury, to consider a court-martial.

“It’s unfathomable,” said Donald J. Guter, a retired rear admiral and former judge advocate general of the Navy, in charge of all its lawyers. “It really does look like this was intended just to bury this.

Navy officials defended the handling of the case, saying the SEAL captain who oversaw it had had full authority to decide it as he saw fit. The captain, Robert E. Smith, who was then in charge of SEALs based on the East Coast and is now a military assistant to the secretary of the Navy, said in a recent statement that the Team 2 members had denied abusing the detainees.

Captain Smith said that he had found inconsistencies in the soldiers’ accounts when they were questioned five months later, and that conflicting statements from the Army and Navy witnesses “did not give me enough confidence in their overall accuracy to hold the accused accountable for assaults or abuse, or warrant Article 32 proceedings.”

While he said it was “evident” that the Afghan militiamen had mistreated the detainees and that the SEALs had not reported it, he dismissed charges for failing to make such a report.

What happened in Kalach involved just one death in a conflict that has taken thousands of lives, but it had broader consequences. Instead of winning over the local population, the goal of the mission, the reported abuse further alienated villagers. It drove some previously cooperative Afghans to leave for Taliban-controlled areas, residents said.

The SEALs’ failure to restrain the Afghan Local Police, who were supposed to protect villages but instead often terrorized them, helped erode confidence in the American and Afghan governments, whose forces have repeatedly been accused of abusing or killing civilians.

During the United States’ engagement in Afghanistan, now stretching into its 15th year, the American military has expanded the mandate for SEALs, sometimes assigning them roles for which they are neither suited nor trained.

Brushing away serious charges, military justice experts said, reflects a breakdown of accountability that feeds the perception that SEALs and other elite Special Operations units get undue leeway when it comes to discipline. In murky wars with unclear battle lines, they warned, that can corrode ethical clarity and undermine morale.

“What’s the message for the 10,000 guys that were in the same moment and said, ‘No, we’re not crossing this line’?” asked Geoffrey S. Corn, a former military lawyer who was the Army’s senior expert adviser on the law of war. “It diminishes the immense courage it takes to maintain that line between legitimate and illegitimate violence.”

This account of the events at Kalach, in southern Afghanistan’s Oruzgan Province, and how the Navy handled them is based on interviews with dozens of current and former military personnel. Reporters located victims and other villagers in Afghanistan and tracked down the four American soldiers who made the abuse allegations, who are now scattered across the United States. Most were initially reluctant to speak.

A Guide to the N.C.I.S. Investigative Report

A review of the documents provides vivid details of the detainee abuse reported at a military outpost at Kalach, Afghanistan.

The Times also obtained the report prepared by the Naval Criminal Investigative Service, including sworn statements by Army, Navy and Afghan witnesses. All names were redacted in the document, acquired through the Freedom of Information Act, but several people familiar with the investigation confirmed them. The report was reviewed by four former military lawyers and a civilian military law expert.

In addition to describing misconduct by the SEALs, villagers complained that the Americans had empowered the local militia to act with impunity — taking goods from shops in the market, ransacking homes and delivering a rifle butt to the belly of those who resisted them.

The Afghan militiamen in Kalach “were like dogs, and the Americans were the masters,” said Hajji Ahmad Khan Muslim Gizabe, a prominent elder there. “The masters would follow behind the dogs, telling them what to do.”

Mr. Gizabe said that he had been among the Afghans who aided Hamid Karzai, the future president, in 2001 when he was flown into Oruzgan with American forces to foment resistance to the Taliban. But after what happened in 2012, he said, “I cannot support the Americans.”

The small base at Kalach was just a speck in Afghanistan’s rugged terrain, dwarfed by the mountains behind it. The stone wall surrounding the outpost was barely chest-high, offering little protection from a Taliban attack. The objective was to get Americans close to the people they were training, instead of living behind high blast walls and shiny razor wire like most of the troops in the United States-led coalition in Afghanistan.

The West has more to do with the Hong Kong protest movement than it would like us to know. It’s the ugly face of Washington’s long-standing foreign policy directed at destabilizing one of its long-standing economic foes: China.

The same media that has spent years dragging Assange’s name through the mud is now engaging in a blackout on his treatment. If you are waiting for corporate media pundits to defend freedom of the press, you’re going to be disappointed.

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